HELP

What is the best way to answer questions with a x expression in the question. for example 3x + 10x=?

Abarbecue sold 26 hamburgers and hot dogs. hamburgers sell for $3.50 each and hot dogs sell for $2.00 each. if the barbecue made $70 in sales, determine and state the number of hot dogs sold.

Paul’s car is 18 feet long. he is making a model of his car that is 1/6 the actual size. what is the length of the model?